This invention relates to new and useful improvements in devices for selectively controlling the number of operating cylinders in a multi-cylinder internal combustion engine.
Many attempts have been made to restrict the operation of some of the cylinders of a multi-cylinder engine once the vehicle has reached operating speed in an attempt to reduce the fuel consumption thereof.
These are particularly applicable for use with V-6 or V-8 engines which utilize either two or four barrels with half the barrels being operatively connected to half of the cylinders and the other half of the barrels being operatively connected to the other half of the cylinders in a relatively balanced relationship.
Examples known to applicant include U.S. Pat. No. 4,098,252 which utilizes the disconnection of the fuel pump from the cylinders not being used. U.S. Pat. No. 4,161,166 is controlled by placing the inlet and exhaust valve of the unwanted or unused cylinders in an inoperative position.
U.S. Pat. No. 4,124,012 shuts off the fuel on the cylinders not being used and venting is by end shifting of the interior of the spark plug. U.S. Pat. Nos. 4,019,479 shows a split type engine which is controlled by throttle valves and 4,135,484 shows a split type engine in which the two groups of cylinders are controlled by the operation and manipulation of the fuel lines by means of solenoids and the like.
U.S. Pat. No. 4,080,948 utilizes a sliding shuttle valve which is adapted to allow both barrels of the carburettor to communicate with the two groups of cylinders when in one position but allows only one barrel to operate when in the other position and at the same time provides venting to the unused cylinders. A third position is also provided which is intermediate position in order to smooth out the transition from one position to another.
All of these suffer from many disadvantages which include difficulty in venting of the unused cylinders so that the engine is not working against full compression of these unused cylinders and the difficulty in relieving the vacuum on the intake strokes of the unused cylinders which tends to permit oil to be pumped past the piston rings.
Other disadvantages include extremely involved mechanical and/or electrical apparatus and difficulty in providing devices which can be retrofitted to existing engines.
The present invention overcomes all of these disadvantages by providing an assembly which is easily retrofitted or which alternatively can be installed during manufacture.
In accordance with the invention there is provided a device for selectively controlling the number of operative cylinders in a multi-cylinder internal combustion engine which includes a multi--barrel carburettor and an attaching flange therefor, with half of the barrels being operatively connected to half of the cylinders and the other half of the barrels being operatively connected to the other half of the cylinders, intake manifolds operatively connected between the barrels and the cylinders operatively connected thereto; comprising in combination a valve assembly operatively connected between the half of the barrels of the carburettor and the manifold operatively connected thereto, said valve assembly being movable from a barrel shut off position to a barrel open position and vice versa, means to move the valve assembly from one position to the other position and relief air intake means between atmosphere and said manifold, said air intake means being operatively connected to said manifold when said valve assembly is in the barrel shut off position and disconnected from said manifold when said valve assembly is in the barrel open position.
Another advantage of the present invention is to provide a device of the character herewithin described which may, if desired, include metering plates within the communication apertures between the carburettor and the intake manifold which not only balance the two manifolds when the device is in operation but also can be used to restrict the maximum amount of fuel/air mixture delivered by the carburettor when same is wide open so that the top speed of the engine may be limited, for example, to close to the existing speed limit of 55 miles per hour in the United States.
Another advantage of the present invention is to provide a device of the character herewithin described which is preferably manually operated but can, of course, readily be adopted for use to automatic operation if desired.
A still further advantage of the invention is to provide a device of the character herewithin described which is simple in construction, economical in manufacture and otherwise well suited to the purpose for which it is designed.
With the foregoing in view, and other advantages as will become apparent to those skilled in the art to which this invention relates as this specification proceeds, the invention is herein described by reference to the accompanying drawings forming a part hereof, which includes a description of the preferred typical embodiment of the principles of the present invention, in which: